Used for water distribution, the Delaware Aqueduct in New York, USA is the longest tunnel in the world (as of 2010). Drilled through solid rock, it reaches a staggering 137 kilometres (85 miles) in length. More tunnel facts.

In the last 4000 years, no new animals have been domesticated.

Hawaii is the only U.S. state never to report a temperature of zero degrees F or below.